Abstract
Purpose: :
To study the clinical significance of idiopathic epiretinal membrane (ERM) with localized contraction on the basis of the clinical and morphological characteristics observed on spectral-domain optical coherence tomography (OCT).
Methods: :
The authors performed a retrospective study on 34 patients (34 eyes) with idiopathic ERM, who received pars plana vitrectomy at Kyoto University Hospital from January to July, 2008. Three eyes were excluded from the data set as their color fundus photographs were unclear; further, 5 eyes were excluded because they did not receive OCT examinations. Twenty-six eyes were included in this study. We defined localized contraction of epiretinal membrane with radial folds on fundus photographs as "the focus (of contraction)." We classified the eyes with ERM into 2 groups, i.e. those with and without "the focus;" further, we compared them with regard to age, visual acuity (logMAR), mean foveal thickness (RTvue-100®; Optovue), configuration of ERM (Spectralis®; Heidelberg Engineering), refraction, and retinal sensitivity (Microperimeter-1, MP-1®; Nidek). We employed unpaired t-test to compare continuous data between groups and Fisher's exact test to analyze differences in categorical data.
Results: :
Fourteen eyes (53.8%) showed focus. Compared with the no focus group, the focus group members were significantly younger (66.5 yrs vs. 73.4 yrs; P = 0.028), and showed thicker foveal thickness (515 µm vs. 421 µm; P = 0.004), worse logMAR visual acuity (0.44 vs. 0.26; P = 0.041), higher myopic refraction (-1.47 vs. 0.90; P = 0.02), and greater frequency of ERM tear occurrence on Spectralis® (13 eyes vs. 7eyes; P = 0.042). Six eyes (42.9%) of the focus group had spindle-shaped white turbidity apart from the focus observed on color fundus photographs. Cross-sectional imaging with Spectralis® revealed that the spindle-shaped white turbidity corresponded to rolled-up edge of the ERM tear. All of the 6 eyes showed decrease in retinal sensitivity on MP-1 that was associated with the white turbidity.
Conclusions: :
Our results suggest that eyes with ERM that were complicated with the focus of the contraction possess thicker fovea and worse visual acuity. Contraction of ERM appears to be the cause of ERM tear formation, which may be associated with local disturbance of visual function.
Keywords: retina • imaging/image analysis: clinical • retinal adhesion